This invention relates to an openable casing for personal tabletop use, containing a stack of cards on which the user may list, alphabetically or otherwise, the names, addresses, telephone numbers and other pertinent data of persons and/or organizations with which he is associated. More specifically, the invention deals with improvements in such a tabletop directory casing containing a stack of tab-indexed cards and permitting the user to gain ready access to desired entries merely by selective manual depression of the tabs exposed on the front end of the casing.
In the tabletop directory casing of the type under consideration, it has been customary, as shown and described in Japanese Patent Publication No. 14175/1975, to support the stack of cards horizontally on a base structure, with the cards being normally enclosed in a pivotal top cover which is spring biased in the opening direction. Upon manual depression of any selected one of the tabs of the cards projecting forwardly out of the top cover, the card or cards overlying the card having the selected tab are turned upwardly with the top cover, as by being engaged by a pair of laterally spaced engaging levers mounted within the top cover adjacent its front end.
Since, however, the stack of cards is mounted horizontally on the base structure according to the prior art, as pointed out above, a desired spacing is often not formed between the front end portions of the depressed card and the one lying immediately thereover. As a consequence, the levers may fail to positively engage the card or cards to be raised with the top cover. Such defective operation is particularly liable to occur when a card at or near the bottom end of the stack is depressed, and is almost inevitable with cards which have been in use for an extended length of time or which have become damp as in rainy seasons.